Cleaning records. How often really?

What a cute breed some of you are. I suppose, you never clean your shoes either or maybe once. Ebm sounds like a true New Yorker to me, there are truckloads of people like these around here.
Albert, thank you, you rarely write these days, but when you do it is always good.

inna - why the insults and condescending remarks?

Dougdeacon, 5-10% is a lot, especially if they are your favourite records.

Agreed. That was an off-the-cuff guesstimate. Actual # is probably lower.

It is hard for the records not to get contaminated to a degree while playing, the environment is not sterile

Other than trace amounts of airborne dust, which is easily removed by de-static and dry brush, what sources of contamination are there? I de-static and brush each side immediately after it's played. It's rare for anything at all to come off the record. I also re-cleaned and re-rinsed repeatedly when first developing my regimen. The final form of the regimen (which includes 2 ultra pure water rinses) produced results that additional cleanings/rinses almost never improved upon.

And how do you know that the first cleaning was perfect unless you clean again?

I use my ears, which are well trained. I can listen to most any record (in my system) and tell you whether it needs cleaning, or not. I did so many times while developing my cleaning regimen. I've since done it while entertaining friends and their (supposedly) clean records.

What to listen for? It's not surface noise or the lack thereof, except in this unexpected sense: a totally silent record surface indicates that the record grooves are NOT perfectly clean. A perfectly clean groovewall has imperfections that are audible in a good system. Those imperfections are the first thing masked by any layer of contamination. If I hear them, the record is clean. If I don't, it isn't.

Once the last layer of contamination is removed, the record will play with the fullest possible micro-dynamics and clarity. Since we don't always know what those should be on an unfamiliar record, they're a secondary indicator, although of course they're a primary source of enjoyment (certainly more than groovewall noise, lol).

Hope that clarifies.

Dougdeacon, it's good to know about totally silent records. I just never thought of that. But I always listen for the clarity first and noise second.
I don' think that brush can remove everything. Imagine, as an example, that while playing records you sometimes smoke or cook. You'll get some of that stuff on your records.
In any case, it appears that the old guard here agree that at least some records do need re-cleaning from time to time. But I don't envy those who have thousands of records that just might need re-cleaning. Out of curiosity I just cleaned a few records that I cleaned a few days ago and played a few times. I didn't hear a difference. I use Okki Nokki machine and Audio Intelligent three step cleaning solutions, and I have a modest rig, though it is quite sensitive to whatever you change. Not this time.

I give each new acquisition a thorough cleaning (currently with the Audio Desk Systeme) and I rarely find a need to clean the record again. I suppose some light dust may deposit on the record while it is playing, but, that stuff is pushed out of the way by the stylus and has no impact on the sound.

I don't lightly brush my records before or after each playing because I don't think that most brushes do anything but move around the dust on the top surface of the record and INCREASE the static charge on the surface.

I also keep my platter very clean and I cover the platter when the player is not in use (I use an old Charlie Rich album someone gave me for that purpose).

I have not noticed any increase in noise or other obvious degradation in sound quality of my records even after repeated playing.

If maintenance of the records, stylus and player were as elaborate and demanding as some seem to make it, I would have given up on records a long time ago.