Rated 5 out of 5 stars
I started using this addon right after Mozilla removed the screen to ask if & what you wanted to del when closing Firefox. I find it very useful because I don't always want to del private data if I'm just restarting Firefox. No idea why Mozilla thought it was good to remove that feature.
Never had a problem w/ this addon conflicting w/ anything that I use. Unless you want to delete all your cookie permissions, DON'T check "Site Preferences" to clear - this will clear all cookie permissions. I don't know why Mozilla (and Ask for Sanitize) used the term "site preferences" in the clear private data screen, when they are actually "permissions," stored in, what else, the "permissions.sqlite" file. Kinda misleading.