Numbers 19:8

19:8 The one who burns it ¹  must wash his clothes in water and bathe himself in water. He will be ceremonially unclean until evening.

Numbers 19:22

19:22 And whatever the unclean person touches will be unclean, and the person who touches it will be unclean until evening.’”

[19:8]  ¹ sn Here the text makes clear that he had at least one assistant.