I assume it is easy to find DEET products once in Thailand, particularly Bangkok? We like to travel all carryon (atleast on the way there) and therefore won't be able to carry on a large supply of a DEET product.

I can recommed "Jaico"; it is to get in Thailands supermarkets and drugstores.

Many Thanks once again to all responders. We decided to take a tour combination to Thailand and Cambodia last Jan.-Feb.for 17days. Brought Deet and Caladryl. Used Deet when I thought it could be helpful. But never saw a nasty....
Our tour was low budget but valu-packed. Visiting these countries was beyond anything we read or in our expectations! Many meals were not included so we ate "on the street" with the locals.
Oh, the generousity of the people, the sights we saw, the experiences we had, etc. We are very senior senior travelers and hope that we have enough time to revisit these countries once more.