I have never tried a DSLR on the 50, I have a 70D and a 80D. I use an ASI 120 and 174 for imaging, I had talked with lowjiber about the best way to take pics with it. I think the barlow, say a 2x might work because I have noticed with my LS80 that when I put in a barlow I have to extend the diagonal further out of the diagonal.

I know with an ASI camera you have to add an extension tube (25mm?) to the front of the diagonal so you can pull it further out of the focuser you also have to unscrew the eyepiece holder from the top of the diagonal and the 1 1/4" nose piece off the camera and then screw the camera right to the diagonal.
With the Canon you would need a 1 1/4" nosepiece with a Canon tread to put in place of your lens and then I would try a 2x barlow and put the camera in that and the whole thing into the eyepiece holder on the top of the diagonal and see if you can get focus.
My concern is that even with the barlow there might not be enough focus range to reach focus.

We are supposed to have sun on Wednesday and I will try it out myself.. One thing I would look for is a barlow like the Meades that are shorty barlows, with a lens right at the base of it so it would pick up light right at the BF