I don't have a link handy, but we have one of those Perfect Pour 1oz flasks for our bleach. The screw-on caps both split pretty quickly. We ended up finding a supplier of that style of bottle and ordering a bag of caps. Polyethylene dosing bottles are available from various industrial packaging supply companies. You might have to buy 10 to make the shipping worthwhile, but much cheaper than the one-off price through that famous online bookstore that seems more like a bazaar these days. Seems like a natural for TF-TestKits to stock.