I like the camo scheme a lot. Indeed the Lufwaffe seamed to use water solible paint for winter washes, hence it wore off rather quickly.
Most of it was brush painted, as it was a field modification, but on larger airfields it was sometimes spray painted.
All camo was done at unit level, hence the large differences in how the winter camo was aplied.
Most was done over the existing paint, so most aircraft wore 70/71 over 65 before the winter wash was aplied.
The so called "wellermüster" "wave patterns" were also sometimes used for winter washes and night bombing operations on the Ju 87. Though adding a "blue hue" like RLM 76 mostly was done for maritime operations.
It was also used on Fighter and Jabo aircraft for maritime operations. (For exapmle KG 54's Ju-88's, KG 2's Do 217's and the Eisenmeer JG)
I guess it all depended on the availble paintstocks at unit level. Most likely the reason why a lot of late war aircraft wore non standard camo.
Also the Luftwaffe rebuild a lot of damaged aircraft in field depo's, where sometimes parts of different airframes was used to rebuild an aircraft, thus mixing parts and camo schemes.
(thoug a different subject all together)
As for the Stuka/Ju 87 D, I'm no expert on this subject, so if used for anti shipping, the RLM 76 wave lines may have been used, most likely prior to the winter wash.