Part of the bathtub mythos involves the following, which gave us all kinds of gruesome ideas: the Countess of Bathory, often used in mythos as a historical figure that might have been a vampire, bathed in the blood of virgins, convinced that it would make her immortal. Therefore, we decided that the tub required the blood of virgins in order to work. Filling a tub requires an AWFUL lot of blood.
The main source our villain considered for this was actually children, since they're pretty much guaranteed virgins. He summoned up a spirit to go sniffing out virgins and stealing their blood, then carry it all back to the tub. As a result, a higher-than-usual number of children were dying at the Children's Hospital, and a PC who happened to still be a virgin ended up in a problematic spot-- especially when the villain realised he now had a sample of her fresh blood for Thaumaturgical use, if he could only separate it out.
All food for thought.