I dont think they flip burgers at McD.
To answer your question .... I suppose it would be "possible" to carry ICK with water on the LR.... Do you have any fish in the tank that the LR is going into? you could hold off adding fish for a month or put the LR in quarantine for a month if you wanted to be absolutely sure... If it were me ... I dont think I would worry about it too much...
So, IMO...
theoretically, yes ick could ride in on rock or even water...
a real issue?.... probably not, unless you have an overstocked tank or the fish are somehow stressed.