Making an entrance using an old fleshlight works, but the fleshlight material is a little sticky/tacky. TPE seems to be better and you can get a Doc Johnson “The Tube” cut to size and hold on with zip tie: https://www.amazon.com/Doc-Johnson-Tube-Masturbator-Clear/dp/B0027CU1MQ
But even this is not ideal as the inner diameter is small 20mm (0.78in) which means its a bit tight on the receiver and doesn’t want to stay on (hence the zip tie) and for me it grips the foreskin too much instead of sliding.
The best mouth is one I made myself from SmoothOn EcoFlex 00-10 which is custom shaped and sized.
