Buff WhiteLight X1600: paint inside of snoot silver?

Feb 15, 2015
Just ordered a second studio flash (have a Buff Einstein 640), a Buff WhiteLight X1600. Mainly for the uncoated tube to do UV reflectance macro. In order to control excess spill of harmful UV, I got a snoot, but that loses 3.5 f-stops. Snoots generally are black on the inside. Has anybody painted it silver? or glued aluminum foil on the inside? How much difference does it make? Just in case you wonder, I don't want to paint it white because of the ubiquitous fluorescent UV brighteners in white colors.