I always tied myself to the platform when doing VC10 Speed Topping runs (103% on military VC10s) One guy at BA didn't and he was sucked out from under the engine into the intake. Fortunately for him, unlike the CFM56, the Conway has guide vanes ahead of the first set of blades, but the poor chap still lost a hand and some of his other fingers. Also, the engine surge that resulted from him blocking the intake blew him back out again and its a long way down from a VC10 intake.
If a specific task takes you near the intake, wear a harness - and don't forget that wind affects the safety zones too.