Liquid Sandpaper


Hi - Has anybody used this liquid sandpaper stuff on the interior prior to applying a coat of varnish, or have any comments one way or the other? The original varnish on my boat still looks good and there is no need to remove it to the bare wood. But I would like to put on a fresh new coat or two, and don't like the idea of trying to lightly sand all those rib edges or the planking between them!! Al