[DIYbio] Extracting and drying human DNA

Hello DIYbiologists,

i planed to do (qualititativ) detection reactions of the atoms, which my DNA is build of. Therefor i need lots of DNA. To extract DNA i used the saltwater-dishcleaner-alcohol-method(used spiritus instead of iso-propanol, worked better in my case). The problem is that i also get lots of bacterial DNA using this method. Do you have any method to extract human DNA with much less bacteria DNA, without hurt and provide a good amount DNA per charge and can be done multiple times in a row. Due i have support from a chemistry teacher i can access some chemicals.
I do not ask for a method to replicate the DNA after extracted with nucleoacidsand thermocycler.

Do you have an idea for DNA extracting, which woks better in bigger scale than the described method?

Thanks for inspiration, literature, ideas or protocols