thanks for your info... my problem was that also .. i was not sure how to wash it off properly .. and another thing which i hope is not damaging... i tend to leave it on my face for close to 30mins !I've found the key with this is patience and persistence. You won't see instant results, but I've seen a big reduction in blackheads over 6 weeks. My routine is as follows with MB Silver powder;
Apply thinly, wait for 15 mins. Then fill the basin with hot water and a few drops of tea tree oil. 'Steam' the powder off, rubbing gently with the flannel.
Do this twice or three times weekly and there will eventually be results!
Good luck!