If rinsing the bottles as soon as they are poured, there shouldn't be any gunk inside, correct?
That is what I do, empty the bottle, rinse with hot water and drain in a FastRack.
When ready to bottle, I soak in PBW, rinse and submerge in Starsan
The fast pitch canned wort is an instant yeast starter, which normally would be used with liquid yeast. No need to boil or use DME.
As @mac_1103 stated, direct pitching the dry yeast may be all that you need to do, depending on what kit you have.