I suggest that you have a good coughing and throat-clearing session beforehand, perhaps followed by a swig of water, and then restrain yourself during the sitting. As the bhikkhus of old restrained themselves:
"Again, venerable sir, being a head-anointed noble king, I am able to have executed those who should be executed, to fine those who should be fined, to exile those who should be exiled. Yet when I am sitting in council, they break in and interrupt me. Though I say: ‘Gentlemen, do not break in and interrupt me when I am sitting in council; wait till the end of my speech,’ still they break in and interrupt me. But here I see bhikkhus while the Blessed One is teaching the Dhamma to an assembly of several hundred followers and then there is not even the sound of a disciple of the Blessed One coughing or clearing his throat. Once the Blessed One was teaching the Dhamma to an assembly of several hundred followers and there a disciple of his cleared his throat. Thereupon one of his companions in the holy life nudged him with his knee to indicate: ‘Be quiet, venerable sir, make no noise; the Blessed One, the Teacher, is teaching us the Dhamma.’ I thought: ‘It is wonderful, it is marvellous how an assembly can be so well disciplined without force or weapon!’ Indeed, I do not see any other assembly elsewhere so well disciplined. This too, venerable sir, is why I infer according to Dhamma about the Blessed One: ‘The Blessed One is fully enlightened, the Dhamma is well proclaimed by the Blessed One, the Sangha of the Blessed One’s disciples is practising the good way.’"
(Dhammacetiya Sutta, MN. 89)