How far along is it? Is it in a rockwool cube or anything? I got a hydro clone in rockwool, put it in soil for 4 days, then switched it back to hydro. It's still alive and doesn't seem too stressed from it.
Rinse it with distilled (preferrably pH balanced) water too. That'll help get some of the soil off. It's ok if some of the soil stays, it'll get cleaned off in the hydro setup and when you change your reservoirs it'll be gone forever