Ok il pick some up tomorow 
It's just that it's been specifically designed for that purpose, it won't harm the rubber seals at all, in fact it will keep them supple, and it will protect the outer surface of your pistons from rust, whilst preventing dirt and salt from reaching the seals which can break them down or damage them.
I will clean mine at least once, preferably twice a year, and just a toothbrush and brake cleaner scrubs them up really well before i re-grease them again.
It's something i like to take my time doing so i can sit outside on the first predicted sunny warm day after winter has finally gone away.
