The only time I clean my 2 Achilles RDAs is if the flavor gets funky, or, in the EXTREMELY RARE event of using a different flavor; my preferred method of cleaning is to boil them, so I don't need to use any chemicals that might leave a residue or odor.
When I used clear glass driptips, I swabbed out frequently, and rinsed daily, mainly because the condensate inside is so unsightly. When I use metal driptips, I have to rinse them pretty often because the "lip smut" builds up and feels icky. Which is why I mostly use acrylic driptips; they're not clear, so I don't see the condensate, and either lip smut doesn't build up, or I simply don't feel it. So I only clean those when I notice that the o-ring around the base is getting yellow-brown and kinda icky.
Of course, I use 86% PG, so no need to worry about any microbial growth; any microbes that can survive that much PG, I probably don't have anything to kill 'em anyway.
No Agent Orange or carbolic acid around here! And I wouldn't dare use bleach on attys or driptips, because the stink lingers, and would definitely mess up the taste.
Mods... I clean them immediately if any ejuice gets on them, or if normal smudges and fingerprints begin to look unsightly. I wouldn't be able to tolerate brass or copper mods; I'm a slob, yet a slob with a strong OCD streak, and the constant patina'ing would drive me bonkers. Brushed stainless, thankfully, doesn't have that problem, nor does painted/enameled metal.
Andria