If you're a DIY'er you can always buy MX in bulk, weigh it out on a milligram scale, mix it in 60% rubbing alcohol and 40% purified water, and just plop it on your head.
https://www.google.ca/search?as_q=buy+bulk+minoxidil+powder&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=&as_occt=any&safe=images&as_filetype=&tbs=
I've thought about doing this