We can carry the Salagrama deities while travelling abroad in a wooden box wrapped in a shawl or silk cloth, with a count of 3, 4 or 7 Salagrama murtis. One can continue the tirvuaradhanam there by performing the first thirumanjanam in milk.
Notes:
Sometimes when you check in, the officers have the right to inspect the belongings; in that case we are forced to show them the deities as sometimes they might appear like a metal during scanning. The officers might have to touch the deities. It is important to cleanse the deities by performing thirumanjanam in milk during tiruvaradhanam.
So, some say it is better to wrap the deities with layers of silk cloth so that it cannot be seen while scanning and take utmost care to carry Perumal hygienically.