CAN ANYONE RECOMMEND A PRODUCT  I CAN BUY TO PUT AT THE BOTTTOM OF MY APPLIANCES TO STOP FOOD DEBRIS ROLLING UNDERNEATH?

I had a poorly fitted kitchen previously, we now have a brand new kitchen however we kept our old washing machine (its a great washing machine)  so it is not fitted like our other appliances, and this means there is a slight gap under the washing machine. 

 I know from previous experience its near impossible to clear out any mess from under there unless you disconnect the whole washing machine and pull it out, which is very hard to do. Can yourecommend a product i can buy to prevent debris rolling under there in the first place.  I remember someone saying something about "plinth" but I looked on Amazon for a plinth and couldnt find anything that fits the bill.  ALternatively if you have any other recommendations I would love to hear them