Rub n' buff

Several years ago i used rub n' buff products quite a bit on aircraft.  it was great fo r weathering and also great for small parts... Some years have passed and I ran out of my tube of Silver and I went back to try and find it, but could find it ..  Now I see many references to the stuff in model building (Recent) magazines and tips,  Could anyone advise where the rub n' buff products are and who sells them?...thanks so much...Lavarr.e