Chad's videos helped me tons for chem (I scored 24). In my experience, the cDAT asked much more concept-based questions rather than calculation based, but I'm sure you have heard of this tons already. So focus on actually understanding the concepts, the ideas, how formal charges are assigned, what the difference between the different explanations of acids/bases are etc. etc. etc. But you still have to know the calculations ofc, it's just knowing the concepts help make the calculations easier to do (or sometimes, not necessary altogether).
I personally used Orgoman's DATDestroyer's Chemistry section and practiced the concept-based questions. I did them all (around 450 questions), then redid the ones I found hard in preparing for the DAT. It helps you save Crusher practice tests too until closer to the date.
One last tip that worked for me; the way I like to study is to reiterate and teach myself (or better yet, someone else) the material. I re-wrote ALL my notes from the top of my head on notebooks 3-4 times throughout my studying. And ofc I'd check my previous notes if I wasn't sure about something. I learned very quickly this way; especially in Bio. It works for me, idk if it would for you but just saying.
