'via direct url' responds slowly. clear all option?

hello,

so i use the ‘add files’ ‘via direct url’ a lot.
how can i clear this segment of all url entries at once?

in infuse 6 it takes me now half a minute (ipad 2016) until the ‘adding banner’ appears.
one reason might be that i probably accumulated hundreds of entries in ‘via direct url’ segment and it would take me hours to delete them.
the deleting process is also way more unresponsive and slower than in infuse 5.
so only for this reason i switched back to infuse 5.

hope anyone can help me figure out how i can bulk delete these entries. thanks.