Have you confirmed its really a wart with a dermatologist?. Its a good idea to do so, although some warts are very obvious.
Aldara is one of the options for GW. However, some articles stated that it is more effective for minimally keratinized warts (ie may not be effective for warts with harded skin)
Try and finish your course (I thought it has 12 sachets per box). If you think it is not working and dont want to finish it, you might want to consider Podophyllotoxin? Although Podophyllotoxin is also said to be ineffective for
highly keratinised warts
It is said that ppl with warts usually will have lesser outbreaks as they age
So, I am not sure of such truth.
You may want to read my reply about Gardasil vaccination :
Would be interesting if Gardasil reduces outbreaks in later years
Although it is not meant for treating warts, but preventing infection