I have a variation that I use for online sign-ups only. I have to explicitly declare the alias before using it. So it’s relatively easy to check which ones I have used in the past (and the name tells me which site I used it for) and I can easily “revoke” by removing the alias. I can’t really use it when asked for an email address at a store, for example - but it doesn’t happen that often (going to real stores, I mean :) )