If we are going to make up new symbols for mathematical objects for every new presentation, why not use a, b, c, d, ... instead of ξxi1, ξxi2, ξxi3, …?
In fact we can be even simpler by using blocks of colour. Instead of calling the elements of a free group something that requires learning an alphabet, just use blobs / circles / squares coloured red, green, blue, yellow, purple --- these are just as good elements of a free basis as x_1, x_2, x_3, ....
If I get hit by a truck in the next year, somebody look through my papers and pick up the task of making a watercolour children's-book exposition of schemes and cohomology.
If, in fact, they are as simple as Grothendieck claimed, then you should be able to show them to a pre-linguistic person [cave of dreams, mcluhanisms, lurya, harpers] and they could get insight into it.