You can use car geek apc available at auto x or I am selling koch chemie mzr if you want.
But be sure to protect all those parts
For seat I will recommend you to clean with apc and then apply sonax leather care lotion
For headliner spray some apc on brush and then agitate (don't spray it directly)
For seatbelt use some cloth brush with apc and agitate it hardly.
For connector and dashboard use apc with brush and then protect it with tac system seal or carpro perl or meg natural shine protectant.
Be sure to vaccum floor first and last both.
Use proper detailing brushes and tools