Vinyl cleaning - Ultrasonic vs. Walker products

Most guys would rather spend the money than do the work and if that is you then go US. It is probably faster, certainly easier, but whether it gets as good results as Walker I have to wonder. 

Walker wins hands down in terms of cost-effectiveness. At least as good as US for a fraction of the cost. Walker charges a lot for their kits but their refills are very reasonably priced and so I bought just the refills, use my old Disc Doctor brushes and this brings the cost way down. Also use my old VPI to vacuum off the final 2 rinses. 

That is the only thing it is used for. A big problem with all cleaning systems is to eliminate all traces of your cleaning solutions. The problem with VPI, if the brush gets even slightly contaminated then it is smearing dirt not cleaning. Same for US, it cleans the first record everything after that goes into dirtier and dirtier cleaning solution. 

Don't drink the Cool-Aid. To get a record clean is easy as pie. To get a record perfectly clean is almost impossible. Walker and some other multi-step processes will get you there, but it is laborious and time consuming. Frankly, for a lot of records, probably not worth it. Inherit 200 records, be real happy if 20 are worth cleaning at all. You will have ones that skip, are noisy, or just not anything you would ever listen to. 

I would put em in two piles- ones you might like, ones you might not. Maybe clean a few you are pretty sure will be worth it. The vast majority I would decide after playing what if anything it is worth cleaning.

Right now it seems like you want US just because you have a lot of records. This way you realize nah, could do em 20 at a time with Walker, not such a big deal, maybe never even clean a lot of em.

I have been using a Nitty Gritty for ages, and it is a must when you have second hand vinyl. The VPI and other record cleaners which use a cleaning solution and vacuum combinations do the same thing as the basic Nitty Gritty does, just with more convenience, but exact same efficiency.The NG is good enough when you have a low-fi mid-fi system. If you want to make the record super clean, then NG treat it several times! I have an 1812 overture that was an unlistenable wild campfire with some background music, and it has cleaned up to a very dynamic and enjoyable record after cleaning it five times with the NG. (Did not remove ll the noise, but turned  frisby into a playable, and more importantly, enjoyable record.)
When you have a very high resolution system, then you can take advantage of the ultrasound (US) cleaner. I have a DIY US cleaner that I have been using for 5+ years. For a very good system, you can clean 4 records at the same spin, and hear MAJOR improvement, as if they have been NG 3-5 times. In case you have a system with the highest resolving power, then you are kicked back to US one record at a time, and you will hear major improvement VS multiple records sonicated at once, or ran through NG multiple times. If you have a large record collection and a top notch system  then the US cleaner is a must - otherwise you are missing out 90% of your collections potential. For example, a record that sounds quite poorly can clean up to give a superb experience. You do not know what is on the record until it is clean... especially in the bass. With dirty records you are missing out the lowest octave entirely.
That's my experience. (I have an audio buddy, and he had the same experience with US cleaning.)

Ultrasonic is superior.  I learned this from experience and formulated my opinion.  I had a very expensive VPI cleaner top of the line (like 4K), vacuum etc.  It cleaned my records well and I had no complaints.  There was noticeable improvement on some of my used LP purchases.
Then I read a thread on Audiogon not much more than 2 1/2 months ago on the subject of LP cleaning.  An engineer in this group talked about his Digital Ultrasonic Cleaner that he paid $150.00 for and raved about it.  I figured for $150 I didn't have a lot to lose and I'd sell which ever one performed the lesser of the two. 
I bought it.  Instructions were not too good.  I think it's made in China, but the pictures were enough to figure everything out.  I put it to work.  I can do 5 records at a time, no sweat.  It is amazing how clean the ultrasonic has gotten my records.  As it vibrates the water and infiltrates the grooves, it cause tiny particulates to fall to the bottom of the silver tank/pan.  I could see in the bottom of the pan from records I had already cleaned with my VPI, specs of dirt that came loose.  As a bonus I even shined up some of my wife's jewelry using it.  
So now my VPI is up for sale.  I will gladly give you a good price on it if you want to go that route.  Otherwise if you want to go ultrasonic just log on line and type in Digital Ultrasonic Cleaner and see if they still come up.  Good luck.

@normantaylor - are you using more than just distilled water?  Any surfactants or detergents or alcohol in you pr US cleaner?