Cleaning a viv that used to house an RI snake

Unfortunately the last ball python I bought from Pets at Home (mistake, I realize now) died from Stomatitis and RI. The symptoms were showing within the first few days of me owning the snake, and after a check with the vet he confirmed my temps and setup were correct but the move from the shop to my house may have pushed the infections into full gear. Pets at Home also recommended some nasty aspen bedding with a lot of dust that aggravated the snakes condition. I have now decided to purchase another from a private breeder. I don't have the money to splash out on an entire new viv with new equipment, so I am picking up some reptile disinfectant with my new buddy and will give the viv a large scrub down. This will be on Tuesday. In the meantime, does anyone have any recommendations of ways that I can fully ensure my viv and it's hides, bowls ect ect is perfectly clean? Using a small wooden viv with glass slider panels. I've already wiped it with normal disinfectant and let the bowl and hide soak in hot water for 20 mins.

I may sound way over the top but I would feel horrendous if another ball python died because of a mistake that I made - I felt bad enough even when pets at home were to blame for the first.

P.S. Also important - the heating in my house has buckled recently and my room isn't as warm as it should be. Over the last week (even though no snake has been in the viv) I've been monitoring the temps. Heat mat is all the way up and I'm still only sitting at about 30 degrees in the hot hide :( Cold side is at about 22 - is this enough? As I said the heat mat is all the way up. Is there any safe way of installing a heat lamp? I know they are strongly opposed but my room can get cold during the night and I'd like to make sure the snake is sitting at at least 32/33 on the hot side. The viv is tall - I don't think there would be any snake+lamp interaction. I will make sure the lamp is covered. Thoughts?

Appreciate any help in advance, and thank you.

- Lewis.