It's open for discussion. I try to do an enema 6 - 8 hours before the flush. I get my olive oil and lemon's organized, clean the place up, tidy up the bathroom. Then I relax , meditate for a bit. Watch tv, read. but I don't do anything that will tax me. Then I take a nice long warm bath a couple of hours before...smile.
Next day after the flush I do an enema around noon, or whenever is convenient, then one late evening or early the next day. Its a comfort zone thingie.