You could put a few short strips of them in a single glass 35mm slide mount, and simply print without even taking them out. You should be able to fit two rows of three in each mount. Almost three rows of three, but not quite.
I know I'm not answering the question, but the genuine Minox storage sleeves are still available (at least in the UK from Retrophotographic) and I don't think you'll find safer than them. In my opinion they're not that expensive for what they do and if people don't buy them they won't be manufactured (assuming they still are :confused
Minox sleeves work best, but they are very expensive and hard to find. You can put the negatives in regular 35mm negative protectors. It looks rather strange, and they sort of get lost, but it basically works. One roll fits in two 35mm slots, but 8.5mm strips are short and may become difficult to retrieve. Even so, it's probably the easiest way to do things.
I use the same negative pages I use for 35mm. Each Minox roll, when cut in half is about the same length as six frames of 35mm. So each page holds 3 Minox rolls (six strips of 18 frames).
If I shot more Minox, I'd probably try that trick with the soldering iron. Or, in my case, I have a 'vacuum bagger' that can make a continuous 'heat weld.'