to buy or not to buy (ultrasonic record cleaner)

When I hesitantly decided to get back into vinyl, I wasn’t sure about it or putting big money into it.  So I bought a TT for under $300 and got a SpinClean.  I go far beyond the SpinClean’s recommendations of a few spins, as the records I had were never cleaned more than using a Discwasher before each play, and some records I inherited might never have been cleaned.  After numerous spins in each direction, and then wiping the records with the supplied cloths, followed by air drying, I played the record.  If it still didn’t sound great, I would clean a second or third time.  That seemed to work fine on most records, but some were apparently too damaged to be saved.

After using up the supplied SpinClean cleaning liquid, I searched the internet for a home-made facsimile and decided on 2/3 distilled water, 1/3 91% isopropyl alcohol and a couple of drops of dishwashing liquid in a 8 ozs. container.  A couple of SpinClean capfuls in distilled water in the tank, and that seems to work fine.

I still can’t justify paying thousands of dollars for a cleaning machine to clean records I only play on occasion.  

You can manually clean pretty effectively without spending a lot of money. One of the issues isn't just whether the chemistry is effective, but how easy it is to remove from the record without leaving a residue that includes the chemistry plus contaminants.
Rinsing is good. But dishwashing detergent is pretty heavy. Dawn was popular with car detailers to strip off wax build up before they would get to work on a painted or clear coat surface. It has a lot of stuff in it that you don't need for cleaning records. Cheap yes. I think you can do better without spending much more.  

Here's the 2nd Edition of Neil Antin's Precision Aqueous Cleaning of Vinyl Records. It expands on the chemistry and processes, and includes a much expanded section on ultrasonic chemistry and processes. Not a light read, but an excellent reference. It is a free download. Neil did all the work; I just published it. 
https://thevinylpress.com/precision-aqueous-cleaning-of-vinyl-records-2nd-edition/

@whart 

Thanks. Will curl it out. 

For those that already have extensive experience with an ultrasonic, is there any prep you do prior to use?  Visual inspection for any blemishes or material that probably should be removed with a fingernail or something?

I bought some used ones the other day and ran them through my (admittedly low-end) ultrasonic and they are pretty clean and shiny now, but, I found the cleaner won't get rid of things like the chunk of chewing gum (small, almost not noticeable) that some prior owner left deposited on the vinyl. 

Of course they also don't seem to be able to clean up 100% (although considerably) the results of many many abusive plays over the years by owners who had probably played them on groove-grinder turntables with dust all over the stylus and/or coin taped on the cartridge head to keep the needle in the groove.  The LPs quiet up considerably after a clean in the ultrasonic but can never be made perfect again if they have been damaged, at least in my opinion.