YOU TIGHT LOT
How much is a squeegee rubber? When I was trad, I always started each new day with a new rubber edge, so either a new rubber or turned around the one I put in the previous day.
Normal use will soon wear the edge off the rubber and start to wear the corners. Why faff around trying to squeeze an extra day or two from a dodgy rubber - it's less than 50p an edge, start afresh
Two other points: always wipe the rubber all the way along before every new pane, and I was always suspicious of the holder in the BOAB - I thought the hard plastic edge could easily damage the rubber so I always used a soft leather holster for the squeegee.