blender pickup up and dropping object -- setting visual keyframes just changes position? I'm trying to make a systematic way of pickup up and dropping objects in blender (2.8, so no dynamic parent addon).

What I've done so far is to add a child of constraint to the object being pickup up, set the parent to a specific bone, then pick up it and move it around with keframing the influence etc... then when I try to DROP it the issue comes.

WHat I've been doing is, once keyframing the influence back to zero and seeing the object reset to its original position, just manually repositioning and rerotating it to approximately the same position as last frame... But as you can gueess, that is pretty ridiculous to do, there should be a way to copy the position it was at on the last frame. 

I was looking on here and I found someone said to say to keyframe the visual location/rotation the frame right before setting the child of influence to 0 and then duplicate it to the next frame, but when I simply add any "visual" keyframe (while the child-of constraint is still on), it moves the position to some completely different place ?()?

Anyone can easily duplicate this by making an armature, then adding a child-of constraint to another object etc... and when you get the influence to 1, just try adding a visual keyframe.

Why does it mess it up, and how can I fix this / drop an object easier (WITHOUT dynamic parent addon since it doesnt work in 2.80)
This is the best method I've found pick up and drop and object using the aforementioned child of constraint with an additional copy location and copy rotation constraint on that same object. Then animating the influence siders of the copy location and copy rotation constraint to achieve the desired effect. There is no need to animate the child of influence slider using this method - you can keep the child of influence slider to full strength: 1.000.