Having only recently begun to build up a window cleaning round, can someone advise me on the best length for squeegee channel rubbers. Should I cut them the exact same length as the channel (so that the rubber is totally straight within the channel, or should I cut them oversize and then force them back into the channel (so that they have a rippled look within the channel)? Does either method help in maintaining a smooth and graceful action while maintaining contact with the glass at all times? I seem to be having trouble with the rubber blade 'grabbing' and jumping off the glass when changing direction. Or is it just practice? Thanks.