I have used the hot fix ones for several projects and they have stayed on through many many wearings and washings...
I got them from hotfixqueen.com -the swaroski kind - i bought the tool but don't use it - actually a pain - rather i just lay down the crystals in a pattern that I want and then place apeice of parchment carefully over them and iron them on...
I have made tiaras, cinderellas coach and mickey heads to great effect!
I noticed the iron on ones at Hobby Lobby, but didn't know if they would stay on or not. I started to buy one of the bedazzler type machines, guess i should be glad I didn't now though! Thanks for the info.! Have a great day!