It was a few years ago, so we had to join a “club” to put our house in a catalogue, which was then posted out to us. We then wrote or phoned possible swappees to ask if they were interested, and if so, when.
Most UK swaps were arranged via the NCT. I think now Mumsnet has a similar system.
Now I guess it’s all online and therefore much easier.
In practice, Germans & Scandis are keener to come to the UK, than vice versa. The Canadians, 50/50. We live in Bristol so described our location as close to Bath, as more foreigners know it as a tourist destination.
We swapped cars with the Canucks, not the Euros. It all worked well although there was a little damage a couple of years. You just have to have trust, and they have to trust you. It helps if you’re not too houseproud and don’t mind other people sniffing your knicker drawer & using your sex toys.
It was much better than renting villas, as the kids had toys, the kitchens were fully equipped, we had entertainment systems for the rainy days & neighbours to help.