Bandit, just to clarify, what i described wasn't my proceedure, its actually already on the club site, link below:
http://bxclub.co.uk/diy/struts/
The only bit it doesn't cover is adding the 3in1 oil through the hole at the strut top mount. I agree, ideally you shuldnt use wd40 etc...but if all else fails, then the amount of contamination is so low i'd take the risk anyway, as i suspect the lhm in the cars system is probably old anyway, a good excuse to change it for fresh lhm or even hydraflush after having sprayed away onto the piston if its very noisy.
As to the benefits, i've had varied success, but in all cases there has been an improvement (which i repeat regularly every 6k), its probably dependent upon how much crap is in the struts as the fresh lhm in the bottle has gone mud brown before, so not sure where it settles within the strut, possibly at the bottom? & so the citreobics must unsettle it. I also when there is crap in the bottle, i replace it with fresh lhm & continue to keep doing so until it stops making it manky. Even if this crap gets into the system, it should end up at the bottom of the main lhm tank due to its swirl design & plastic plate trap, simple & reasonably effective system.
I agree with Phil about lhm lubricating the strut piston/washer, others have also commented that its a waste of time, hence 3in1 oil was suggested to me by a few people. Again you dont want to be pouring loads of the stuff onto the piston, just a few drops.
Give it a try, you will only waste some time if it doesnt work & you never know, it may breathe a bit of extra life into the struts & stop any annoying groans. I think its should be part of a normal service, so when changing the oil & filters etc...i tend to give them a workout at the same time.
