Technically, PVC pipe can be used as a conduit. In fact, grey PVC pipe is manufactured precisely for this purpose. You could use PVC made for water since it's the same thing but with a different gauge (thickness). It might not pass an electrical inspection but it would certainly work.

Several different systems make up a house's water systems. Fresh water is delivered to a home through water supply pipes from the utility or a well and is then distributed to sinks, toilets, washers, bathtubs, and related fixtures. The drain-waste-vent system carries away used water and wastes to sewers or septic tanks.

PVC conduit, is always a great choice, primarily because of the economy and it also protects from water that may seep into the wall. PVC conduits are also used in cases when electric wire may need to run below the ground or in an open environment that is exposed to air, dust, and water.