We propose a new method for 'indirectly' measuring 235U NMR parameters in uranium intermetallic compounds which contain ligand nuclei observable by NMR. The spin-echo decay of 103Rh NMR has been measured in both 235U-enriched and non-enriched URh3. It was found that the 235U enrichment in URh3 induces an additional Lorentzian decay process for the 103Rh nuclear spin-echo decay through unlike spin-spin coupling. This cross-relaxation effect allowed us to estimate the T1 of 235U to be T1T ~ 2 s K in URh3. No such measurement has, to our knowledge, ever been reported for an actinide intermetallic compound.