Using the same material as support can be difficult to remove and very messy. With multi material printers you can use PLA as support for PETG or PETG as support for PLA. Standard material as support are also much cheaper than PVA for example. 

And the best it is much easier to remove:

PLA as Support for PETG	PETG as Support for PETG

Instructions

Load the cube in your slicer and select a different material than the support material for the cube.

3mf for…

I have uploaded a 3mf file for the following printers:

• Prusa MMU2s (self printed)
• Bambi Lab Printer with AMS (!!! I do not have a Bambu Lab printer.)

Thank you. 
If something is wrong, just ask. 
Seb