thrips?

It's possible that this is a type of scale, I think. My aspidistra suddenly developed a bunch of white flecks this fall. I believe the soil was infested when I picked the plant up from the garden center.

Euonymus scale, just based on an image search, looks like it could be the culprit. The recommended treatment is horticultural oils, which suffocate the pests (the label should tell you what pests are affected).

My infestation is not heavy, so I have been using rubbing alcohol until it is time to repot in early summer, although I'm not sure that's ideal.

I would isolate the plant ASAP to limit spread of the infestation. While you wait for a definite ID, I would take a spray bottle and spray that leaf with some isopropyl (rubbing) alcohol. Try different mixtures-too strong may cause damage to the leaf, while too weak won't affect the pests. Start with a 50/50 water and alcohol, then try slowly raising the amount of alcohol. Once you've found the best ratio of alcohol and water, spray the entire plant-branches, leaves, everything. After that, wait around 3-6 more days before spraying again (to get the newly hatched pests).

Best of luck!