This expression is nearly always used in the negative.
This expression may have been derived by the 10-foot poles that river boatmen used to pole their boats with, along in shallow water, or from the barge poles that bargemen used to fend off wharfs and other boats.
Many believe this expression originates from a burial practice in New Orleans. The Spanish developed burial system of present day proceeds by first placing the casket of the patron in an above ground tomb. Exactly 1 year and 1 day after burial, the tomb is opened and the casket removed. The body is next wrapped in a sheet and shoved to the bottom of the tomb using a ten foot pole. The weather of the area caused the remains to decompose quickly and tombs are subsequently reused for many burial. The expression, "I wouldn't touch it with a ten foot pole," is thought to have originated from this burial process.