Oakum
Oakum can be used to seal cast iron pipe drains. After setting the pipes together, workers pack oakum into the joints, then pour molten lead into the joint to create a permanent seal. The oakum swells and seals the joint, the "tar" in the oakum prevents rot, and the lead keeps the joint physically tight.
Today, modern methods, such as rubber seals (for example, gaskets or o-rings) are more common.
Trap primer
A trap primer (or trap seal primer) is a plumbing device or valve that adds water to traps. The water seals in traps are needed to prevent sewer gases from entering buildings, but because this water is exposed to the air, it is subject to evaporation over time in infrequently used floor drains, leading to the release of sewer gas into the environment. The trap primer mitigates this problem by injecting water, either directly or indirectly, into the trap to maintain the water seal indefinitely.