Glazing putty

Hey, my friend told me to use glazing putty (comes from Bondo brand in a tube, red putty stuff) anyway he told me to use this to fill my pinholes... he's a good body worker so I took his word, then I took my truck to the shop for paint... guess what, all the pinholes are back! The prep/cleaner shit they used must have washed all the putty out of the pinholes. I had heard not to use this stuff before but my buddy gave me his word that this stuff is the bomb. Anyone else had this problem?