A report about clearing the throat is also narrated from Abdullah bin Nujayy (may Allah have mercy on him), but Abu Zur'ah is not mentioned in its chain.
In another chain, saying tasbih is mentioned.
However it may be, Abdullah bin Nujayy is not one whose narrations are used as proof.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3342