my DVD player no longer reads DVD RW's, but still reads regular dvd's, what

Are you sure you finalised the DVD RW when recording to it, as some DVD players require it to be finalised before it will play, use what ever you did to record to it and see if it need finalising or closing

RW DVD and RW CD are very sensitive. Even DVD/CD home made are not as good as the commercial ones. Anyway - a DVD lense cleaner would help if the problem is only with dust/other stuff on laser lense. There could be also dust on the track lens causing a slight delay in reaching the desired track - and returning NO DISC. So, use a lense cleaner but clean also the lense track.

hope it helps.