This DIY recipe to make playdough is from my wife. It's natural ingredient and practically much more harmless than whatever play-dough or Plasticine you can get from marts.
The step by step as written by her shared here:
Update: no need store into fridge. Salt keeps them lasting in room temp.
1/2 cup salt, 1 cup flour, 1 cup cooking oil. Mix well.
Add water color as described above.
Cook for 5 min, medium to low fire.
Knead with spatula.
Ready for play!
Store in glass container, can last for months.
Video from Play-Doh.
.now try to make Olaf XD