Besides cutting the hair or applying conditioner or oils, what else can be done to remove hardened dough from hair?  Would vinegar dissolve hardened flour?   Update: The lump is an odd consistency: between a live dough (super gluey) and tough and with a slight give, very slight. I feel like the gluten is being released and water is both releasing it and releasing a few hairs. Any strands of hair that can be freed seem to have live dough on them which, if not cleaned, contaminate other clean stands. Pushing/ scrubbing with the nails is the only, and very hard, way to get that tiny sticky amount out of the individual hairs. A shampoo with sodium lauryl sulfate helps, but it is still very hard.   I am wondering if there is an enzyme that dissolves gluten. A quick online search recommended tablets for people with who cannot tolerate gluten, not I am not sure if I open the pill tablet and apply it to the hair, it will work.   
Ouch, sounds rough.  Soak it in cold water.  This may be awkward; depending on how thick the dough is, it might require soaking it for an hour.  But it's really the best way. 