"Cross" is very short in British English dialects, meanwhile "sauce" is much closer to "source", to the point that they're almost indistinguishable. American English dialects tend to elongate the "ahh" sounds.

Sauce: I used to speak in American, but now I speak in bastardised English where I trip off the path and whipe my ass on the grass, but no one ever knows how I might pronounce those words.