Handamerican is a company name that is well known in circles where superior edges and advanced sharpening techniques are discussed. Their sprays are guaranteed to be of uniform particle size and is used in conjunction with sharpening stones and other compounds.
These sprays are normally used in two ways; 1) As a final polishing step after your finishing stone, and just before your final strop on leather, or, 2) a means used to get a dulling blade back into shape for extensive use prior to refreshing it on whetstones. I have not done the latter and it would be interesting to learn just how long a blade will remain comfortable to shave with by only touching it up on felt with this products every now and again, please send us some feedback if you can add value in this matter.
The stuff is extremely economic and will last for yonkers, so I'd certainly advise on getting some regardless whether you are a casual user, or a professional user sharpening lots of blades on a regular basis, the results are very satisfying, and it is simple to use.
It is advised you stick to the one particle size per medium you use to strop on, so try to have a strop/wood block/canvas/wool felt dedicated to each spray you buy. You can also use the backside of your SA leather strop as the chosen medium for this spray, I'd sand it down a bit with 180 and then 320 sandpaper followed by a good blast from a compressed air gun to make sure no sandpaper particles remain.
Shake well, two or three squirts on the surface that you will be stropping on, and leave it to dry for a few minutes. Now go to town on that razor, you will note the bevel polishing up almost instantly, this stuff really works well and is a great step to include in your honing regime.
Some Q&A here. There are a few more videos on the net, but I suggest simply getting into using the stuff and finding what works best for you.