How to delete several channels?

[tmanni]

There is no way to delete several channels in one action in 2.10.
You can do it only programmatically.
Open the python console menu Filters > Python-Fu > Console ; these 2 lines do the job (assuming you have only one image opened)

Code:

img = gimp.image_list()[0]
[img.remove_channel(c) for c in img.channels]