Flasks 10, 110, 210 and 310 serve as a storage container for toothbrushes 2, 2A and serve are reservoirs for a treating solution, such as a cleaner, which can be used to clean, deodorize, sanitize, decontaminate or otherwise treat the toothbrush between brushings. Flask 10 has an upper section 14 separated from a lower section 22 by an intermediate section 18, which contains a constricted throat 20. A toothbrush 2 in an inverted position would be supported by an inwardly tapered surface 16 above the constricted throat 20. Toothbrush bristles 6 would be located in the enlarged lower section 22, which serves as a reservoir for the treating solution. The constricted throat 22 can be sealed so that overpressure in the lower section can enhance the action of the treating solution. A covered flask 110 can also be used to store or merchandise the toothbrush.