If you want 1 product for all the ML powders take a look at Ballistol. You thin it with water for real black and most subs. Use it straight for BH209 and centerfires. It has the same main ingredient as Montanna Xtreme. Only the solvent base is slightly different. It uses a type of alcohol and MX uses a type of ether.

I do REALLY like the MX Bore Conditioner for short to mid length storage. IMO there are better rust preventers but if your bore is clean, dry then oiled rust wont be an issue anyway.

As mentioned just avoid Teflon products IN the bore. They serve no purpose IN a bore. The only thing they can do is have a negative reaction to heat when fired.

BTW a great product for drying a bore cleaned with water or to remove oils is non chlorinated brake cleaner. Just dont get it on plastics or the stock finish to be safe. It evaporates quickly taking the water/oil with it. It is rather toxic though so only use in extremely well ventilated areas.