"[...] I don't notice the strip I've placed there,"
I use a similar system for four times a day. Even though they sit in front of the PC screen - I occasionally overlook them when engrossed in El Reg comments.
The next pill is there in clear sight - already out of its blister pack to remind me - and I still don't always see it.
The suggestion by Stoneshop above - of a preprogrammed flashing red button is definitely the way to go. Just have to remember not to cancel the alarm until the pill has been swallowed. One of my Arduino projects has all the bits to do it with a modicum of reprogramming.