How long do you get with a bottle ste?Do you have to apply it on a dry surface?Can you offer it as an extra and put price up to cover cost,does customer notice it`s been applied,how long does it take to dry and when its dry do you just brush over it or is that it,sorry about all the questions but i`m interested in this stuff,i reckon that sealer goes grey and dull after a bit and looks greasy.this stuff must stop the sand blowing out the joints does it mate,were do you get it,wicks? thanks