Figure 2: English monosyllables letters examples 7 SQUEEZE, SCREECH, STRETCH, SCRATCH, STRANGE, SQUELCH, SCRUNCH, THOUGHT, BROUGHT 8 SCROUNGE, SCRAUNCH
, BROUGHAM, STRAIGHT, STRENGTH, SQUEEZED, THOUGHTS, STRESSED, STRIPPED 9 SQUELCHED, STRETCHED, SCROUNGED, STRENGTHS, SCREECHED, SCRATCHED, SCRUNCHED, STRAIGHTS 10 SCRAUNCHED
Considerable quantities of ink have been spilled through the years in an attempt to prove that English really does have more examples in the 10 letter category.
If you're going to say that ten-letter SCRAUNCHED
has one syllable, then I suppose you could argue that the eleven-letter SQUIRRELLED or BROUGHAMMED have one syllable.