i dont believe there is such a thing as cutting steroids , but some lend themselves to cutting better in the look achieved , most would start with test e and dbol for example, this encourages good mass gain but some of that mass is due to water retention, when switching to prop and winny at the end, its benefits are 2 fold the short esters of the prop and winny are used to "ride" out the longer esters before a pct protocol is started , it also helps get rid of water retention gained previously and this is what they mean by solidifying gains, so when you come off there isn't a drastic drop in weight as you shed water .
i could just as well bulk on prop / winny combo as i could cut on test e / deca , its all in how you manage your diet and training and what you hope to achieve on the scale . that said there is benefits to both, i like the water retention when bulking as it benefits my strength which in turn benefits muscle gain.
a way of viewing it is for example if the anadrol i am on = 20lbs gain over 6 weeks whereby i stop and lose 10lbs of water = roughly 10lbs vs if i had gone the test prop winny route maybe i would have gained 10 lbs as well with almost no water retention, end result almost the same .
just my 2 c
goodluck
edit : just remember timing, a traditional bulk is 12 (well for me at the bare minimun) you dont want to be running winny much past 6 weeks at a massive push, this is where the other compounds come into play running test / deca or test and eq for 12 to 14 weeks is fine, also ed pinning over 12-14 weeks becomes a real pain the ass , so many other aspects to take into consideration)