I'm really sick of seeing oil seepage on the tube coming from the valve cover into the air intake, going to the turbo(isuzu 4jb1t)...
you are not alone with such annoying situation. same is true with my lc80 with 1hd-t engine. oil is all over from the valve cover breather outlet up to the air inlet of the turbo. this was what i found when i cleaned the tubing/piping; in fact oil has solidified and flaked at the hose around the turbo air inlet.

so the solution? i installed an oil catch can, and lo, very minimal oil mist going into the airbox. the heavy molecules, mostly, oil and blow-by products of combustion are trapped inside the oil catch can. you need not buy from those expensive products out there in the web, simply do a home-made diy project. search the web and you will will find several diy projects illustrated therein, and get an inspiration from one of them. i am still with the prototype testing stage, but already the results are encouraging. once i am fully convinced of the effectivity of the can, i plan to build one using a 4-inch diameter, schedule 40 pvc pipe, with a capacity of about 2 liters.

good luck.