Yes, you can use slingloads in P3D. Some of the slingload object config parameters have to adjusted to get object stability. But once that is done everything works pretty well.
The parameters that need to be adjusted are:
Length and Width in the Geometry Section (both have to be set to 18000)
Empty Weight in the Mass Properties Section (must be set to at least 1000)
The empty weight value can cause problems for small Helo, but, for 212, 412, H60, etc. not a problem.
Danny