Thank you all so much for your input! Yes, it IS an Easter Cactus - you got me on that one! As soon as I posted I knew I was wrong! When I bought it this spring, I thought it was just a Christmas cactus gone crazy blooming that time of year, but I wasn’t about to tell it that! I attempted the running alcohol on a q-tip solution when I initially noticed the problem (maybe a week ago?). It was hard to get the dot off - it looked like an orange/brown dot with a clear layer of slime over the top (probably a bad description!), and didn’t immediately come off, but eventually did once I “helped” it a bit more with some harder pressure. The plant is outdoors and is in the shade most of the time. If it gets any sun it’s afternoon sun. I water once a week, but I have a moisture meter and check the moisture first. Right now it’s reading as very moist/wet, which, I know, is not a good thing. It was potted in a mix of cactus/succulent soil, sand, and pearlite, so it should be draining well. I’m in California where it’s been 100°+ for a while, so the fact that it is not drying out is a little worrisome. Hopefully I watered it recently and forgot! The pebbles on the top were a deterrent to gnats that I read about, and I also like the look. However, if it’s causing the problem, it’s back to sand for me! yes, Rina, I would love some pics. I took one as close as I could (my phone camera doesn’t like to focus close up when I want it to!) of what I scraped off with a q-tip and alcohol today. Maybe it will help! I’d like to save the plant if at all possible. It’s not huge or terribly sentimental, that’s true, but I’d like to keep it if at all possible, just the same. Thanks again everyone for all of your help!!!

Tyler, sorry for not being specific. I meant alternating between solution application (of either, but not both, IME) and then water blast, for however many cycles of this you need (even heavily-scaled stuff like the OP's) - I'd just leave the solution on for 5 minutes or so, then reapply, wait a few minutes, then blast and repeat as needed. It is a distinct pleasure to watch the pest get peeled away from the plant by the carefully-applied water stream, let me tell you. Kara, it is that simple, but I'm still glad I wasn't drinking anything when I read your comment.

I do not grow opuntia, so maybe I shouldn't comment. Here is my question: IIRC, corking starts at the base of the plant. I can't tell from he photo if it does or not. Corking is normal for many (maybe all???) cacti. It is usually relatively slow process. But if brown spots apear in other spots on plant, and suddenly, rather than at the base, it is a problem - caused by pests disease or damage.

Might it be corking at the bottom? It isn't uncommon for the older parts of cacti to become corky as they age. It doesn't look as nice but it is normal.