Hello feelnrite.  I think this is a "try it and see" situation.  The physical characteristics of the liquid, the hay, and the bale make this quite variable as to how much you can get into a bale without wasting any.  I would lay some old plastic under the first bales you do to try and determine fairly accurately just how much, if any, is seeping through.  It seems in my situation that the product I use would rather coat the hay than soak into it.  And it seems like it finds the path of least resistance to run through the bale to the ground.  And once it finds that path, more follows it.  And so if you put too much on the bale OR let it sit on its side to long you will notice not only that it runs through to the ground (snow) but in only a couple areas (as opposed to uniform penetration into the bale...)

(When I set them in the round bale feeders, I take the net wrap off and set them in normal position and there isn't any seepage while it is being consumed.)

I don't know how Beefbiz can get so much (10% by weight) on his bales with out wasting any; must be the type of hay and bale characteristics....  Maybe it soaks better into leafy type hay and since I'm treating the poorer quality, later cut stemmy hay it runs through rather than soaks in.....??  But since the cows clean the treated hay up plus get the added nutritional boost of the protein and energy (pointed out by Beefbiz) I am happy with the 4 gallons ($8)/bale!

Hope you come up with a method that works out well for you!  Brian