A few years ago I did some heat shield related pre-Phase A studies for JPL concerning Venus sample return. Most of the concepts involved where baloney and not worth commenting on. One goof ball idea that I informally proposed was "fishing for rocks". Setup a lighter-than-CO2 platform on Venus floating above the sulfuric acid clouds. On the platform have a big spool of gold plated piano wire with a rock scoop attached to the end of it. Unspool the piano wire as the rock scoop descends towards the Venusian surface. Attach buoyancy floats to the piano wire at appropriate intervals (the ultimate tension strength of piano wire could not support its own weight). After the scoop hits bottom, have it grab a rock and then reel it back up to the platform. After a rock arrives on the platform, give it a look and if it looks nice then keep it otherwise toss it back. After a while, a really nice rock would hopefully be found. Shoot it into Venusian orbit from the platfrom with a small ascent rocket. Another vehicle would acquire the sample from Venusian orbit and return it to Earth.

As screwball as this idea is, I think it is more practical than having ascent hardware go all the way to the Venusian surface.

Gary