An Indonesian person might use the following words and phrases to discourage a foreign traveler from pursuing their plan of action:
Lebih baik tidak.
It's better not to.
Sebaiknya jangan.
You'd better not.
Kurang aman.
It's not very safe.
Saya tidak menyarankan itu.
I don't recommend that.
Mungkin lebih baik cari alternatif lain.
Maybe it's better to find another alternative.
Jangan lakukan itu.
Don't do that.
Tidak dianjurkan.
It's not advisable.
Berbahaya.
It's dangerous.
Itu ide yang buruk.
That's a bad idea.
Anda mungkin akan mengalami masalah.
You might get into trouble.
Mengapa tidak mencoba ini?
Why not try this instead?
Lebih baik pergi ke tempat lain.
It's better to go somewhere else.
Ini lebih aman dan nyaman.
This is safer and more comfortable.
Using these phrases, an Indonesian person can effectively communicate their concerns and offer safer or more suitable alternatives to a foreign traveler.