Yeah, check out Secret Life Of Machines 104 The Washing Machine https://www.youtube.com/watch?v=baFaEvBywGc&feature=youtu.be...

they show what happens if you take the block out. Also how comercial machines do without it by balancing the load.

Damn that takes me back! I used to love watch Secret Life of Machines, back in the 80s.

The automatically filled pockets to balance industrial washing machines are very interesting.

Only the cheaper ones use concrete I believe. High-end models use cast iron, because concrete will start to crack/crumble after 10 years

Some very high-end ones use iron counterweights.