Stoner Car CareReach and Clean Tool

What is the differance between the one piece and 2 piece? I orderes the 2 piece thinking i was getting 2 of these but only got 1

Can I use this for cleaning my house windows outside?

Do you spray the invisible glass cleaner on the tool or the window directly? Is the liquid version as good as the can version?

I'd like to know if it works for glass doors ??thanks in advance