For what it's worth, here is what I've found out.
Writing ASHA usually receives a response directing you to your institution. However, in a post above, ASHA did clarify a lab is not required for either the Chem or Physics class.
So the best bet is to just check with your university advisor. ASHA provides accredidation to your university, so they go with what your advisor ok's. But each advisor will ok only what they feel 100% safe ok'ing.
At my institution I had the unique experience of having first one then another advisor. For me, both advisors did not accept a Coursera stats course I took for free/no credit, even though it was taught by a professor from Duke University and was WAY TOUGHER than the subsequent one I took at a local community college online. So, personally I wouldn't advise Coursera, though I love their courses. This was because it was not for credit, so it can't appear on my official transcript.
For my physical sciences requirement, my second advisor is allowing his advisees to take a Geology course. I've googled tons of schools, counted the tuition/fees/registration/textbooks and found most Geology courses are $700 and up. Even my local community college wants $700 for a 4 credit Physics course, the only online course in my county that can satisfy the physical sciences requirement.
So now I've found a 2 credit Physics course at a community college in a neighboring county for $526 not including textbook (no info). Since ASHA doesn't say it has to be a 3 credit course, and usually defers to adivsors, I'm going to ask him if this will work. For me, 2 credits of Physics beat 3 to 4 credits of Geology!
By the way, I'm in my second to last semester before graduation, and I do wish I'd been on the ball and completed these courses in my first 2 much easier semesters of grad school!
Good luck to all of us!