I believe that this idea was invented as an excuse to stay "on". Will it help maintain gains? I don't know. The theory is, take 10mg first thing in the AM and it will have cleared your system by night, when you go to sleep and release the majority of your natural test. At best, I don't believe you will be able to recover completely. Even if you can produce some test at night, I can't believe that you would ever be able to function at 100%. And keep in mind that test isn't only produced at night. There would have to be some blunting. It probably isn't going to be as bad as using a TRT dose of test, but don't fool yourself into thinking that you are totally free and clear. There is no free lunch.
Coming off and losing gains (strength and muscle) is probably one of the biggest fear a steroid using bodybuilder has. If you are still able to produce your own test, I would invest your time, money and effort into that. Run a solid, PCT plan, which may include using a 250iu dose of HCG through the cycle, up to PCT. And focus on getting that diet and training dialed in so that you can maintain the most you can.