do record cleaning fluids soften the treble?

I can understand a solution leaving behind things that fill the tiny grooves that represent the HF information. I'm not understanding how cleaning can soften bass. But then, that is not what I hear, and I prefer to clean all of my LPs. FWIW, YMMV, etc.

Rrm,
I felt that the sound did change and a little softening did occur. One day after playing a record it slipped and I grabbed so it would not hit the floor. I put finger prints all over it so I had to clean it. I had started doing a final rinse after cleaning my records but had not done it to this record because I had cleaned it a while ago. After a cleaning and a rinse I played it again, I found it had better all around sound, better hi's, bass was faster with more impact and the record had much better micro dynamics. I will now reclean the rest as I play them so I can do a final rinse on all records. I clean all record regardless, you can never tell how a record is handled by the manufacturer or dealer

Cleaning new and old lps is a must and a double rinse is the answer for clear noise free playback. What i find very interesting is if you dont include a small amount of a release agent to your rinse water you will leave behind residue.

Dave: Now,now,where then would that leave the others here who favor cleaning more as a matter of routine? Just kidding of course. There's plenty of room in this fascinating pastime for those taking the other road to optimal listening pleasure.

@RRM: Totally agree with the upper octaves (and there are other effects of cleaning too depending upon the fluid!). Another effect I find with fluids is a decrease in transparency, particularly as one listens deeper into the soundstage. It's not what the fluid takes off but how much fluid is left after cleaning. That was one reason that I switched from VPI or Nitty Gritty to other fluids. Like Albert, have found the RRL/MOFI to be much better in this regard, though some other new fluids are also quite good.

@Syntax: One problem with getting all the fluid off the LP is that the surface tension increases as the amount of fluid decreases. That's why some RCM manufacturers have made machines with more powerful or adjustable vacuum capabilities. I do feel however that one runs a risk with the higher vacuum in damaging the LP if the machine isn't properly aligned. There definitely is a difference say between the "ordinary" VPI machines and their Typhoon.