Try it and find out. There's no harm possible.
The answer varies from pedal to pedal. Having never used either of those pedals in the effects loop, I couldn't tell you for certain. But many modulation effects do just fine in the effects loop. Others may be overdriven by a line level signal, but there's no damage possible at that level of voltage and current. Now, put it after your poweramp... and it's a different story. You'd need a fire extinguisher.
Also, in some cases, pedals that worked fine in a guitar amp's effects loop may be overdriven in the effects loop of a bass amp, because of the increased low end output. Again, it's case-by-case and no risk of harm, so give it a shot!
The reason why you'll hear the preference for the effects loop is actually because of guitarists more than bassists. Guitarists who overdrive their preamps and depend on their amps for distortion tend to prefer modulation and time-based effects after the preamp. It's no different than the typical preference of most bassists to place those same effects after overdrive or fuzz pedals. It's simply stemming from a different source.
Bassists don't often use preamp overdrive, and those who do don't often use effects. So generally, you won't see a lot of bassists using effects loops for that reason.
