Upvote:3
"Sprinkling" can refer to either baptism by affusion or by aspersion, as both basically amount to tiny little pours or droplets of water. While it might make sense to couple this practice with infant baptism for "safety" reasons (babies do actually reflexively hold their breath when submerged), that's not the real reason for this form of baptism.
We find in the Didache, which is a first century manual for how the Church does thing, in Chap 7, gives fairly explicit instructions on how to baptise.
And concerning baptism, baptize this way: Having first said all these things, baptize into the name of the Father, and of the Son, and of the Holy Spirit, Matthew 28:19 in living water. But if you have not living water, baptize into other water; and if you can not in cold, in warm. But if you have not either, pour out water thrice upon the head into the name of Father and Son and Holy Spirit. But before the baptism let the baptizer fast, and the baptized, and whatever others can; but you shall order the baptized to fast one or two days before.
The "pour out water thrice" refers to affusion which literally means to pour onto (usually from a shell) or aspersion (perhaps using palm leaves or an aspergilium), which literally means to scatter upon. It can be used with anyone, not just babies. And, never fear, you can get pretty wet with either method!