1 syllable:
baasch, blash, bosch, bosche, bosh, braasch, brosch, brosche, brosh, brosz, closh, dosch, dosh, flosh, frosch, frosh, gaash, ghosh, gosch, grosch, grosh, hasz, hosch, joash, josh, kaash, kosch, kosh, lawshe, losch, losh, mosh, osche, osh, paasch, posch, posh, prosch, quash, quasje, raasch, raash, rosch, rosh, skosh, slosh, splosh, sposh, squash, swash, swosh, tosch, tosh, trosch, wasch, wash

2 syllables:
akash, alqosh, antosh, arccosh, aslosh, awash, b'gosh, backwash, backxwash, bagwash, bewash, blackwash, boswash, brainwash, burwash, by-wash, camosh, carwash, chemosh, chris bosh, cohosh, damrosch, debosh, dogwash, doordash, downwash, drake & josh, dry wash, eyewash, flat wash, galosh, galoshe, garnache, golosh, goloshe, goulash, greenwash, grenache, hand-wash, handwash, hogwash, khamosh, lavosh, limewash, mccosh, milosh, milosz, mouthwash, musquash, nirdosh, oshkosh, outwash, panache, pigwash, prakash, prewash, pugwash, radosh, rain-wash, rainwash, rewash, rondebosch, santosh, sevmash, shipwash, simhash, siwash, stone-wash, stonewash, tatsache, ustashe, whitewash, wish-wash, wood-wash

3 syllables:
acid-wash, acorn squash, beef goulash, color wash, equihash, hackintosh, harry bosch, hubbard squash, machine-wash, machine wash, macintosh, mackintosh, marrow squash, mcintosh, natchitoches, overwash, powerwash, pressure-wash, roman-kosh, stellenbosch, summer squash, tikoloshe, tokoloshe, toribash, turban squash, vandenbosch, water-wash, winter squash, yellow squash

4 syllables:
's-hertogenbosch, buttercup squash, jayaprakash, spaghetti squash

5 syllables:
summer mcintosh

6 syllables:
hungarian goulash