I've been thinking about buying one of the ozone generator things 8-bit Guy used, since it is much less messy and should cover more evenly. There are similar machines on Amazon for $50:
https://www.amazon.com/Generator-machine-Ster … ozone+generator
My idea is to get a large transparent plastic bag, put any yellowed plastic parts into it (even a whole PC case if necessary), fill the bag with ozone and seal it up.
In the summer, I could just put it outside in the sun, and it should work pretty well.
In the winter, I could probably get a large cardboard box, line it with reflective foil (probably be easiest to unseal the seam on the box and then put it back together after it is lined with foil), and put a UV light in the box, along with the bag of ozonated plastic.
I haven't done this yet, but I'm accumulating enough old yellowed computer stuff that I think it'd be worth it to invest in one of the machines. The convenience of not having to slather goop onto electronics (and then worrying about streaking or unevenness) is worth the higher initial outlay of money, and the machine will probably last longer than $50 worth of salon care stuff.
Now for some blitting from the back buffer.