Just to answer a few questions & make a few comments:
1. I received the tool wax (I'll call it wax for want of better short name.) and it turns out that I lied in my last posting. McMaster Carr did add $6.00 to my credit card to cover shipping (total $37.66.)
2. Why would you use it - 1) Corrosion control, 2) Protect from damage if dropped etc., 3) sharp edges that if left exposed can cut & damage & and injure. 4) the wax is oily enough that I'm pretty sure, after a while, it would penetrate into router bit bearings keeping them well lubricated. As you know, oil seems to creep & crawl and get into everything so why not into router bit bearings? The stuff sure leaves a nice oily residue on router bits. I haven't seen a router bit or saw blade yet that won't rust given enough time and I live in a semiarid area.
3. I've used it and it works well. The melting point is 350 degrees (wish it was a bit lower.) I put it in a tin can and melted it with a propane torch but won't do so again, it's pretty messy & cumbersome. Tried an old kitchen slow cooker with water in it and the tin can set in the water. Didn't get hot enough. I may try a small electric frying pan if I can find one on eBay that's small enough, cheap enough, and deep enough. If not, I'll try for a used hot plate and small kitchen pan. You can buy melters but they're expensive.
4. Yes, although I haven't tried it yet, I'm sure the wax would be reusable and I intend to reuse it. There may be a limit to how many times it can be reheated. Time will tell.
5. Toilet wax rings? Sounds handy. It's not designed for rust control but could be helpful as long as there's not something in it that promotes damage or corrosion. I keep a wax furniture polish handy for cast iron surfaces etc. Likely does about the same thing.
6) Now the big question. Is it worth all bother and trouble? For some, the answer would certainly be no. For me --- the jury's still out but I have so much time, bother, and money invested that I'm committed.