You should see a noticable difference in 3 days tops.. more likely over-night.. and Ick generally holds to a 30 day life cycle.. so keep your temps up for a few more weeks and you should be fine. If you've been doing 10% weekly.. do 20% every other day for the next week or 2... and test your water to see if you should be doing more, imo you're liekly going to have some water issues with the addition of the meds. If your not sitting at 40ppm or less on average your 10% weekly should be stepped up... higher levels of nitrates ime will trigger ick ( imo from physical stress on the fish from the higher levels, once I started keeping my nitrates under 60ppm, I haven't had a ick outbreak since.)
IF your still haveing issues after 3 days... as in its getting worse, or the same. then I would start medication... but ime this is rarely needed. iir 1 strain of ick parasite can stand the higher temps and usually requires the meds. But i'm not sure if it's more heresay, or actual fact.