Hi, you really need to look at
https://www.bics.org.uk/as you can get NVQ or city & guilds in cleaning science. its not that hard and you can do it from home with exams under supervision. its worth it cost is not far off what you pay for a day attend course.
The fist year exam is multi choice, project, and presentation. second year is a little harder with lots of essays and written stuff. this is really for management.
My advice do first year. with respect if your anything like me and have reading and writing problems talk to them they understand and can help. many dont go this road because of this and miss out. lets not forget many managers come up though the ranks like I did and have schooling issues. if you do second year exam they will put someone with you to help with the written work which I think is great
Best luck, respects