SoxKeats, I think glass is the best bottle material for storing MMS. As Dawna said, don't use a metal lid/cap. There are lots of glass bottles that use plastic lids. One of the best I have found is 10 fl oz Schweppes bottles found in grocery stores. The caps are plastic and seal very well.
I have noticed that HDPE plastic bottles used for storing MMS (22.4% sodium chlorite solution), seem to crack and leak after a period of time.
There might be a problem with your gold crowns as MMS1 is quite acid. I recently measured a 5 drop dose of MMS1 in 2 fl oz (60 ml) of water at 2.0 pH.
Using
equivalent amounts
of CDS and CDH (1 ml of 3000 ppm CDS and 1 ml of CDH) I measured 4.3 pH (CDS) and 4.7 pH (CDH).