beyond the 13th chord

Yeah, I know what you're thinking: a 13th chord contains all the notes of its scale, so how can you go beyond it? That's a good point, but if you consider that a 13th chord consists of 7 different tones and that there are an available 12 from the total chromatic then there are obviously 5 tones remaining which could be used harmonically (if so desired). Vincent Persichetti goes over this in his fabulous book Twentieth-Century Harmony: Creative Aspects and Practice. He does state that the 'unwieldy' terms of 19th or so aren't normally employed (that is the descriptions, not the chords) but let's just see if we can wield one -- even a bigger one -- anyway.

Consider the following chord:



From the G2 up to the E4 we have a G13 (dominant) chord. When we get back to the G it is sharpened, the sharp 15th. Next in the series is B, but here flattened, so a flat 17th. And so on. It is quite unwieldy to label such a beast:
G13#15b17#19#21#25
(There is no possibility in this type of chord of altering the 23rd to produce a new tone: can you see why?) In this case on a chart it would seem better to indicate something like "TC" (total chromatic) or some such, but seeing a symbol like G13#15 shouldn't pose a real problem...