Awesome to hear duac is working for you!
You could either get another prescription but depending on when you live repeats can be expensive.
Your other option is to find a product, leave on prefered, that is similar to duac. If you don't already know, duac contains a topical antibiotic and benzoyl peroxide. You can't find the same topical antibiotic over the counter (I believe) but you can find benzoyl peroxide creams in most drug stores.
In my opinion if you now start using just a regular cleanser your acne is likely to come back as most acne treatments you need to use them consistently to keep acne away.