If the cloth doesn't keep a good suction, then replace it!  Don't cheat
yourself by doing it the crappy way.  It's better to replace than try
to fix something that is going to go bad in the first place.  You'll just
have to redo what you did the last time all over again in the near future.
Don't try to put a Band-Aid on something that needs to be replaced!
That's my two cents worth.

Regards, Jeff Bridges