Here again, I lack some of the experience that others have in bare ground apps. I do know that some of the herbicides used in bare ground are merely pre-emergent herbicides used at higher rates. Diuron for instance can kill trees at higher rates. Used at lower rates you can achieve Bermuda Release. A thorough rinsing might be all it takes to get the tank clean enough to use lawn chemicals if something like this were used. On the other hand, if Imazapyr were used, I would give the tank a thorough scrub down before using it for lawns I'd like to keep alive. Even then, I might sweat it a little.
It's always better to have dedicated equipment whenever possible to avoid cross contamination and the possibility of costly accidents/mistakes.
"The Poor Fish" circa 1930's: The Poor Fish wouldn't have been caught if he'd known enough to keep his fool mouth shut.