Apologies for the double post, but this is new information relating to the entire topic.

The macro with the 10 castrandom lines appears to work, although with just one comma it tends to gum up anything you might put after it. For example, I stuck those ten lines ahead of my Pally's aggro spam button. Turns out you spend so much time sending Cleanse commands anything you put afterwards doesn't get through as often as it should. It might be possible to get around that with some added commas so that you're only trying to cleanse 1-3 people per button press, and not 3-7.

The macro with one castrandom line and the ten names in it doesn't work. I don't know why, though my hypothesis is that because every [target=playerx] is a valid cast, it either tries to do them all at the same time, similar to the problem I encountered with the 10 line macro, or it stops at the first (or potentially last) valid cast option. Again, maybe this is solveable with issue with enough commas to reduce how many casts you are actually trying to send in at once.

Bottom line, I don't think putting autocleanse at the begining of my spam macro will ever be effective, but it is certainly doable with its own Button.

Oh, and no, castrandom will NOT autoskip any character without something to cleanse. It will just give the "target has nothing to dispel" message.