Electric Toothbrush Refill Savings

I have an Oral-B Spin toothbrush. I like it because it works well. But the refill brushes are extremely overpriced. I have bought generics, and they often don't fit quite right. Nothing is more annoying than when the brush head comes off while you are brushing. So I have devised a simple solution. By adding a small (and I mean tiny) drop of Super Glue inside the refill brush where it touches the plastic (non-spinning) part of the brush handle (usually two drops—one on both sides) I decrease the diameter of the inside portion of the refill and provide a tighter fit. Two cautions about this. First, make sure the super glue has ample time to dry before putting the handle on the refill. Not allowing the glue to dry first will essentially glue the two pieces together. Second, use a small amount of glue. You can always add later if it was not enough. Too much will prevent the refill from sliding onto the brush handle. By using this method, I have been successfully using generic and much cheaper replacements. The last ones were about a dollar apiece through Amazon instead of about $20 for three. That's a huge savings!