getting him hydrated won't hurt... and poop does have a smell, it should smell like well..poop.
tremors, trouble walking etc can be caused by more than just MBD, it can be neurological, heat stress, genetic defect, late stages of adenovirus, poisoning or toxic reaction to something. If your vet you took him to is clueless, then find another vet who is experienced with reptiles. Call around.
Did this vet do any tests? Bloodwork, x-rays etc? OR did he just stick him with needles and gave liquid calcium? Bloodwork will allow a lab to check for many things, such as white blood cell count, infections, toxins etc. X-rays can show bone density, growths or injuries, spinal defects, gout, etc.
B22 posted a good link for finding reptile specializing vets in your area. If too far, talk to the vets in your area, they may be willing to contact the experienced vet and share findings..lab work etc.
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PHLdyPayne