The best thing you can do to ensure sealed beads is to have your tire guy dis-mount the old tires for you, and take the rims home.
Then, use a fine ScotchBrite (or similar) and soapy water on the beads to get them spotless. This also gives you some time to clean the rest of the rim up, too, including the inside and hub-mating surface. Paint is optional.
You now also have the opportunity to get QUALITY steel stems and install them to specs, even using some sealant if you wish. Use sealant that won't later "flow" into your stems, however, as the sensors will clog if it gets into them. My tire guy used "imported" steel stems, and I had problems getting my TPMS sensors to screw on far enough (see Post #5 above). Uggh! Just a head's up!
Clean beads will increase the chances of no leaks.
2004 Terry 250RKS, perfect for the two of us and the pups. It recently replaced our Flagstaff 21FB.
2000 F-350 7.3L CC/LB 4WD Lariat 3:73's