//The sooner they start filling the planes the better.//
You seem to be labouring under a misunderstanding, LadyGC.
The Rwandan facility - for which the UK has paid the Rwandan government £120m to set up - currently has the capacity to house around 100 people at once and process the claims of up to 500 occupants per year. That is about ten a week (with the current numbers of illegal landings running at around 800 a week). So “filling the planes” is not likely to begin any time soon. As well as this initial cost, the government will also pay ongoing running costs for holding those sent there. Estimates of these costs vary, but (depending where you look) can range from £12,000 per person to almost £100,000.
This scheme is pure theatre. It is said it will “deter” migrants from attempting to reach the UK. I’d beg to differ. It can deal with up to 500 people a year (if the UK manages to send that number). It is very likely the total number reaching these shores illegally this year will be approaching 50,000 – a total which will almost certainly be topped next year. So there’s around one chance in a hundred that if you land here you will end up in Africa. If the chances of drowning in the sea do not deter people from attempting the crossing (and bear in mind that has actually happened, whereas nobody has yet been sent to Rwanda), there is no way that the minimal chance of ending up in Africa will.