Comment by adrian_b

You are right, in the filthiest environments nothing else can be as performant as a worm/snake-like robot, even if such robots are inferior to those with wheels or rotary propellers in nice tidy environments.

Moreover, instead of making a robot with arms, which are useful for work, but which are an impediment for moving in a filthy environment, it is better to send multiple vermiform robots, which are designed such as after reaching their destination they are able to cooperate in such a way as to act like a robot with multiple arms (i.e. they should be able to attach to anything in the environment or to another robot with both the anterior end and the posterior end, like leeches).