WASHING MACHINE UK TO BRUSSELS

Presuming that the machine worked beforehand and as long as you have the correct plug or adaptor then it will work

You will have to fit an appropriate electric plug - don't use an adapter as they are not designed for permanent use.
If your machine is hot and cold fill you will have to buy and fit a 'Y' fitting to allow the single Belgian cold fill to supply both UK intake pipes; if it's already cold only there is no adjustment necessary.
You may need to buy and fit adapters to connect the pipework to the Belgian water supply.
There is nothing that should be beyond the capabilities of anyone with the most basic of DIY skills.

Bringi it white goods can be very costly here, be aware the water is very hard unless you have a softener fitted, suggest adding white vinegar to the water or anti calc tablets to reduce amount of detergent and also prevent lime scale.