I like the Walmart Hand towels for $.47 each. I can get 2 to 4 tire dressing applications at each detail and then I just chuck them when they are black and dirty. I 2-fold the rags and get quite a bit of use that way. Each clean side is used per each tire.
I used to use the tire applicators, however, this is cleaner and you can apply more product on easier as the rag can get into the nooks and crannies.
I was buying a foam applicator or a tire applicator at around $2 - $4 a pop and that can add up.
Additionally, if I am just working on the dash with their dressing the rags are more precise. You can go longer with a dedicated Dashboard Rag towel as it does not get as dirty as the tire rags. IMO The rags can have many more uses than a foam or MF applicator.