Is the Walker LP system necessary if one already uses a good RCM?

I didn't know you were so angry, in general.

Synergistic Research pisses me off much more than Lloyd Walker ever could. But SR has staunch supporters.

I wish I were as certain of most anything as you are of everything, Mijo. Yes, I laugh at demagnetizing LPs, yet there are some who swear it made their LP sound better. And there were claims made that tiny bits of ferrous material do get into the vinyl mix from which LPs are derived.  I don't buy it either. What bothered me more about that particular Walker product was the cost.  One could go on to debate the efficacy of many other audio tweaks that seem to have no basis in science, but there are other forums for that, if you can stand it.  Yes, there was some voodoo in other Walker products also, but they are usually well made at least.  What I would balk at is for example the Velocitor "power line enhancer", at $4150 for a six outlet version and which probably contains a few capacitors and/or inductors for isolation. Nothing you couldn't make yourself for no more than $100, but most audiophiles can't or won't DIY.  On a positive note, I used their silver contact enhancer on connections that do not heat up, to great advantage, according to my ears.  Risky on tube pins that get hot because it hardens in place. Lloyd was not much of an inventor, the Proscenium is a beautified and max'd out version of the Mapleknoll turntables of yore, and the lesser products also are a bit on the me-too side, but he was very clever and a very skilled marketer and salesman. Plus he was a fun guy and very attentive to his customers.

Look out for that dust.

I knew Lloyd Walker for a few years before his death. He was a very engaging and interesting guy, and I enjoyed my brief encounters with him. But don’t separate Lloyd who made the world class Proscenium turntable from Lloyd who marketed some devices that could be said to have been "gimmicky". Those two guys were one and the same person. First, in his defense, many/most of his seemingly cockamamie ideas actually worked. Others I would summarize in the nicest way possible as "overpriced". I bought one of his enzyme-based kits and tried to compare its efficacy to that of my VPI HW17 RCM. In the VPI, I use distilled water plus 25% lab grade isopropanol plus a few drops of Triton X100 per half gallon. I cleaned opposite sides of one of my favorite jazz vocal LPs that I’ve owned for more than 30 years now, according to the Walker Audio method vs my VPI RCM method. The HW17 squirts the cleaning solution on the surface of the LP,  brushes in both directions, and offers vacuum suction of the cleaning solution at the end of a run. After both the Walker procedure, on side A, and the VPI RCM procedure on side B, I rinsed with only distilled water and dried both sides using the vacuum suction of the VPI. I have found the rinse to be necessary to remove residua of the cleaning solution(s), and I can hear the difference if I don’t rinse. Unscientific though this comparison was, I gave a very slight edge to the Walker components over my own RCM concoction. But I also concluded that the Walker method was too time consuming and complex for routine use; the difference was not major.

I think I read somewhere that Walker uses enzymes derived from a bacterium, B Subtilis. If so, these are the same enzymes in the laundry cleaner, Shout. I am pretty sure the half-life in powder form would be very long, but I don’t know how long. Shout lasts a very long time on a shelf at room temp, even though the enzymes are in solution.