I always mechanically clean valves by spinning them up in the drill press starting with a scraper and finishing with Scotchbrite, I say always, its probably been a couple of d?cades since I have done so!!!
I have used that type of oven cleaner after tenants have left their usual mess, thinking that I am hard and never reading instructions I did not use gloves, I mean what could go wrong? Its got to be safe if its sold these days right?
The flesh on my hands turned to a white spongy rubbery substance like a corpse fished out of the sea after 2 weeks immersion, I had no feeling and could probably have amputated a digit without knowing, it reminded me of a Tom Sharpe novel where someone put caustic soda in a condom
It all returned to normal after a nights sleep when the blood could circulate, but i was left with the hands of a baby, as squeaky clean as the oven shelves
I think its the same thing all these plastic surgery obsessed Frankenstein women use for a chemical peel!