I think wrapping up at bedtime is retarded because you're supposed to have erections all night long anyways and that alone should keep your flaccid gains locked in. I asked a doctor in the Penis Enlargement field about this and this is his opinion as well. However, you will find many people telling you otherwise. I myself have went for 2-3 hour naps wearing an
extender (PMP - safe to be hard in).
It's really up to your discretion. Monitor your penis and see if it even makes a difference having it wrapped up at night or not. Other options are wearing a Ring Of Power at night (Which I have done - good erections). I personally don't put much stock into things like divosuits or
uncle jim's strapping method (which I own both and have tried) - the latter I have a problem with because the tightness and material causes skin discoloration - but I do own and use an
extender between my hanging sets (on days that I can) and I find it helps.
Divocup is a different story - I think it may be effective for keeping the penis plump all day, but I really don't have the time or effort to fuck around with it. I just wear my
extender and hang my sets.