Thank you for the clarification. It would seem we were talking about two different things but now that I know what you mean I think I can help.
In my experience mixing tobacco with agglutinates and boiling them has never produced the proper consistency or smoking qualities I want in a moassel so I suggest the following tips:
1) Tombac is best suited as a base so I typical use 30-50% of the tobacco used in my recipes. I never wash it for the simple reason that the flavour compounds that exist in tobacco disappear along with the nicotine.
2) Typically I like the remaining tobaccos used in my moaasels to be a mix of bright, flake, Burley tobacco and a decent quality dark Cavendish although the more aromatic style snuff tobaccos are good as well and I have post about uses such stuff in homemade moassels floating around here someplace.
3) I always use high quality molasses, never honey. I've got a thread here about what sort molasses is best for any given application.
3) Don't use vegetable oil or any sort of oil. Glycerin adds a bit of sweetness since it's a sugar but mainly it's added to improve the burn characteristics. Old style products don't use it at all but most of us want more smoke production so we typically smoke stuff with glycerin in it.
4) The flavours you add to a moassel should compliment rather then totally mask the natural flavour of the tobacco/molasses mix. Adding actual herbs has never worked well for me so I add herbal/spice extracts since they are far easier to work with. What you don't want are alcohol, sugar or oil based extracts since they tend to produce nasty flavours when vaporized. I've tried a great many brands of flavour extracts and without a doubt the best by far can be found here at www.lorannoils.com/c-2-lorann-gourmet.aspx
They are expensive but they are strong and you don't need much so it's actually a good value.
5) I've found that homemade moassels are best when the molasses is added at a rate of 5-8g per 25g of tobacco. The essential extracts need to be mixed to taste but if you want some guidelines let me know. After mixing thoroughly you spread the product on a good cookie sheet ( I use volrath cookie sheets) and depending upon the composition of the tobaccos I bake the mix at 175-250F for 2-4 hours depending upon cut and type of tobaccos used in the recipe.
6) After it's done baking I scrap it off into a mixing bowl with a spatula and let it cool. After it's cool I mix in 3-6g of glycerin per 25g of moassel and mix fully.
At that point it's ready to smoke.