You could coax him into making empty cans in order to see how many people will bother to check the actual content. Also shit has many modern connotations. After all, see the opened can:

https://beachpackagingdesign.com/boxvox/opening-can-boite-ou%C2%ADver%C2%ADte-de-pie%C2%ADro-man%C2%ADzo%C2%ADni

In any case, such (art)work reveals a lot.