I would like to study the homotopy theory of the category of pro-objects over a proper model category $M$. $Pro-M$ is endowed with the strict model structure; it seems that functorial functorizations of morphisms in $M$ do not extend to ones for $Pro-M$.
 My question is: which arguments and statements of Hovey's book cannot be applied in the absense of functorial factorizations? In particular, can one apply the dual to the argument used in the proof of Theorem 7.3.1 in Hovey? Though $Pro-M$ is not fibrantly generated, it seems that one can replace Hovey's (co)small object argument here with the one provided by Theorem 6.1 of B. Chorny's paper "A generalization of Quillen’s small object argument"; yet this is not quite clear from www.math.tamu.edu/~plfilho/wk-seminar/Hovey_book.ps p. 186‎
(probably this version of Hovey's argument requires certain correction).

Also, is there an easier way to prove that $Ho(M)$ cogenerates $Ho(Pro-M)$?