You can use "Mane and Tail Detangler...made for horses or even better, a horse detangler gel called "Cowboy Magic". You can spray that (Mane and Tail) on the fur (or rub the gel in your hands and apply) and it will help you to brush out the knots or tangles he has elsewhere that can't be cut out (where you can see) so he doesn't look like he got in a fight with a buzzer, lol.
With Jelly I use a Chris Christensen brush and a regular undercoat rake and a buttercomb. I am sure you can get the same kind of comb cheaper than the Chris Christensen comb I use. The brushes are expensive but truly worth it. I will post links to the ones I have (you don't need as many as I have and I will list them in order that I use the most).
If you can finally get him to tolerate a bath I would use a pet shampoo but stay away from the Hartz brands and Seargents. They are terrible companies and use crappy chemical ingredients, and many dogs have had reactions to them. You can order a tearless shampoo called BioGroom Econogroom from petedge.com or other online retailers. I use this on a lot of my clients who may be sensitive and I really like it because it rinses more easilly than some other shampoos I have used...which will probably be helpful for you. Be sure to dilute the shampoo according to what the label says. Don't use full strength.
For a conditioner, try Downy fabric softener (Original April Fresh kind, don't get the Ultra Downy) and dilute it 8:1 (8 parts water, 1 part Downy) and work into coat and leave on for a few minutes before rinsing thoroughly. Petedge.com and all of the other online pet stores sell shampoo diluting bottles. It would be a good idea to pick two of those up as well if you do go ahead and order the shampoo to make it easier to dilute everything properly.
If he allows you I suggest drying him after all of this or else you will wind up at square one again with knotting. I usually work on Jelly for days after a bath, line combing and brushing, as much as he will tolerate without getting too antsy.
Work on doing small sections at a time with Koda, treating him when he is good. If he is aggressive with you maybe try a basket muzzle. Work on him for a few minutes a day, while treating, and increase how long you work on hi each day. Hopefully it will condition him to allow you to give him a full grooming eventually.
If he has rolled in something specific and has a really stinky spot, try baby wipes or even vinegar and water on the spot for a temporary fix. Also, you can use Dawn dish detergent on a wet hot washcloth and rub real good to get the mess out and rinse with a clean wet washcloth and repeat as necessary.
Here are the links to the grooming tools I suggest for you...
http://www.chrissystems.com/save-on-pet-grooming-products-chris-christensen-factory-outlet.aspx
(scroll to bottom of page and look for A414. This is an awesome brush that really gets through the coat. It is discontinued so it is on sale. I have to order an extra one in case something ever happens to mine)
http://www.chrissystems.com/grooming-tools/brushes-/pet-grooming-show-dog-and-cat-pin-brushes.aspx
(On this page you want the A127 and possibly an A035G)
http://www.chrissystems.com/grooming-tools/pet-grooming-show-dog-and-cat-combs.aspx
(I have the first comb shown, but you can find one cheaper at another place that will do the same job)
http://www.petedge.com/product/Bio-Groom-Groom-N-Fresh-Conditioning-Shampoo/45958.uts
(They don't seem to sell the EconoGroom in a small bottle, just gallons, so I posted this one instead. It seems similar but I don't think it is tearless so be careful and avoid eyes).
http://www.petedge.com/catalog/product.jsp?productId=55311
(This is great for helping to get smaller mats out of the coat so you don't have to scissor them out)
(This is an undercoat rake and helps to remove dead undercoat)
(These are the thinning shears...when you use these to cut out mats it doesn't look as noticeable like it would if you used regular scissors).
http://www.petedge.com/product/Top-Performance-Professional-Mixing-Bottles/44767.uts
(The diluting bottle for shampoo and Downy)