The Snuneymuxw learn to take part in ceremonies or "do work" in the Big House, dancing with the masks of their ancestors. Masks and regalia are an important part of Big House work. Sxwayxwuy masks are unique to the Coast Salish. They are the traditional masks of the Snuneymuxw, carved with a smooth, rounded face, eyes that stand out like pegs, ears that rise from the top of the mask, and sometimes a nose and tongue. Often, the heads of animals such as birds are carved onto the projecting parts of the mask.

Sxwayxwuy dancers prepare for years. They learn Hul'q'umin'um' words and phrases, they train in steps and movement, and they are educated in the protocol of the Big House. Dancers purify or symbolically "wash" themselves through dancing the sxwayxwuy, but they must also take precautions to cleanse themselves of negative energies before they come out to dance. Children are welcomed into adulthood with sxwayxwuy masked dancers and this special mask is used to dance during other important times in a person's life.

Masked sxwayxwuy dancers dress in leggings, rattles and feathers. They come out to the floor of the Big House and circle the flickering light of the hearth fires. The dancers are there at the invitation of the host of the ceremony and will dance to the songs that are requested, rather than dances owned by their families. Dancers can be paid for their work and are admired for their skill and knowledge. The Speaker of the Big House will introduce them and the various parts of the ceremony. Some families display their sxwayxwuy masks all the time, but others feel the masks should be kept hidden, to be taken out only during the special times for ceremonies.