My only comment about using the FloJet fitting and vinyl hose (which is how I do it too) is the length of the hose... Some say 18" some say 2 feet... I find that with the location of my pump, there's no way to get a gallon jug of antifreeze into that space, so a hose that short simply won't reach from the pump to the bottom of the jug.
So, I've got a section of hose that's about 3.5 feet long. It's "long enough" but only if I don't need to move the jug out of the way. Then, I'd be better off with a 4.5' hose. So, before you head to HD or Lowe's for that piece of hose, measure how long you really need, don't rely on the "pump location/jug location" of someone with their water pump in a different place in their trailer....
2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS