Travelling with twins

Hello,

we will be traveling and taking a 12 hr flight next month. My twins will be 9 months old. i also have a 5 year old son. Does anyone have any tips/advice? Anyone experienced flying with babies in a long flight? I use dr.brown bottles for the babies, feeding formula. I won’t be able to clean&sterilize in flight, etc, so how do i go about that. I heard playtex has bottle liners hence easy to use & throw. Should i use those? Any advice is appreciated. TIA.