I wouldn't sweat the compression. But then some people do fold under pressure.
Ya see what you really need is a Fartzen valve. You Ramset that into the Proprieting Pickler, set it to "Rotate", attach the Board Stretcher, now that's a Hendersen Board Stretcher-don't let 'em sell you anything else, fire up the Ion Streamer and you're all set.
Let me know if you have any problems.
L
If you use a Board Stretcher on a Farsten valve you will strip the bayonets.